Welding is an important process in the manufacture and construction of various products and structures. Applications for welding are widespread and used throughout the world, for example, the construction and repair of ships, buildings, bridges, vehicles, and pipe lines, to name a few. Welding may performed in a variety of locations, such as in a factory with a fixed welding operation or on site with a portable welder.
In manual or semi-automated welding a user/operator (i.e. welder) directs welding equipment to make a weld. For example, in arc welding the welder may manually position a welding rod or welding wire and produce a heat generating arc at a weld location. In this type of welding the spacing of the electrode from the weld location is related to the arc produced and to the achievement of optimum melting/fusing of the base and welding rod or wire metals. The quality of such a weld is often directly dependent upon the skill of the welder.
Welders generally rely upon a variety of information when welding. This information includes, for example, current and voltage. Traditionally, welders would need to look at gauges on the control panel of the welding equipment to gain this information. This would require the welder to direct their field of vision away from the welding work area and as such was undesirable.
In the past, efforts have been made to provide welders with information during welding, such as in the method disclosed in U.S. Pat. No. 4,677,277, where current and voltage are monitored to produce an audio indication to the operator as to the condition of the arc in arc welding. However, monitors consisting only of audio arc parameter indicators are hard to hear and interpolate and are not capable of achieving the desired closeness of control and quality of weld often required.
More recently, as disclosed in U.S. Pat. No. 6,242,711, an apparatus for monitoring arc welding has been developed that provides a welder with real-time voltage and current conditions of the welding arc where information in the form of lights, illuminated bar graphs, light projections, illuminated see-through displays, or the like are placed within the visual range of the helmet wearing operator and located in proximity to the helmet viewing window in the helmet. However, in this apparatus a welder must still move their visual focus away from the welding work area in order to focus on the information located proximate to the welding window or the welder must accept the information peripherally while continuing to focus on the welding work area.